Get screenspace to worldspace

Questions
1

How would in a PostProcess get back the worldspace position of a pixel?

This has to be possible? Or even better the “ray” direction of each pixel in worldspace?

2

Send the inverse of viewProjectionMatrix and do a unproject in your shader kind of like here:

3

hmmm, ok in the shader is the sourceXYZ basically
vec3(vUV, depthValue)?

not sure how to get the correct XYZ values, is it UV space I pass it or pixel? Im thinking it must be the camera.maxZ*depth.

4

depth on screen is 0 so (uv, 0)

5

So:

vec3 ssToPos(){
		
		mat4 matrix = world*view;
		matrix *= projection;
		matrix = inverse(matrix);
		vec3 ss = vec3(0.);		
		ss.x = vUV.x / resolution.x * 2. - 1.;
		ss.y = -( vUV.y / resolution.y * 2. - 1.);
		ss.z = 0.0;
		
		vec3 result = vec3(matrix * vec4(ss, 1.0));

		float num = vUV.x * matrix[0][3] + vUV.y * matrix[1][3] + 0.0 * matrix[2][3] + matrix[3][3];

		return result*(1.0/num);
	}

I think?

8

https://playground.babylonjs.com/#63NSAD

Aww what the heck…
So I copy and past it directly from my local and it works like a charm?!?

What would be different from the playground then my local version using the same BJS version?

UPDATE
It was something about my camera min and max z. Once I got rid of those on my local whabam… anyways what would be a way to apply that to my matrices?